Ring shaped spring device

ABSTRACT

A spring device comprising at least one annular support plate defining a ring with a central axis; a plurality of circumferentially spaced, parallel oriented coil springs disposed about the at least one annular plate; and, a plurality of lock assemblies spaced about the plate. Each of the lock assemblies being in position within a spring cavity of one of the coil springs to allow additional springs to be provided on the spring device. In addition, the lock assemblies are dimensioned so that the coil spring is retained in a prestressed condition.

[0001] The present invention relates to a spring device and moreparticularly to a spring device of the type used in automatictransmissions for motor vehicles.

INCORPORATION BY REFERENCE

[0002] Automatic transmissions for vehicles often include a plurality ofcoil springs that are adapted to apply a biasing force against clutchplates that control the engagement of various gears in the transmission.These coil springs are assembled in a ring shaped device comprising twoannular plates having a multiplicity of circumferentially spaced,parallel compression coil springs mounted therebetween. Such a ringshaped spring device is disclosed in Orlowski U.S. Pat. No. 5,306,086,which is incorporated by reference herein as the basic background towhich the present invention is directed. A ring shaped spring device isalso disclosed in pending application Ser. No. 10/078,465 filed on Feb.2, 2002 which is incorporated by reference herein as the basicbackground to which the present invention is directed.

BACKGROUND OF INVENTION

[0003] In the ring shaped spring device disclosed in Orlowski, there isa pair of spaced apart first and second annular support plates definingthe ring shape of the spring device. A plurality of circumferentiallyspaced parallely oriented coil springs are disposed between the annularplates so that vertical movement of one plate toward the othercompresses the springs. To interconnect the plates, an integral hook isformed in one plate and a loop is integrally formed in the other plate.The hook and loop are designed so that the device can be assembled bymerely locating the various coil springs and then pressing one platetoward the other. The hook snaps over the loop to lock the platestogether, with the coil springs partially compressed. However, whenassembled in a transmission, the ring shaped spring device is compressedfurther so that the hook actually disengages the loop. Consequently,during repetitive operation of the spring assembly over many years, theindividual coil springs can become canted in a manner to reduce thespring constant and cause damage and/or unintended biasing forces. Bycompressing the spring device for shifting the gears of the automatictransmission, distortion of the coil springs in the annular direction ismagnified. Consequently, the prior ring shaped spring device, as shownin Orlowski only employs the concept of integral interconnectingelements and does not address the problem of controlling the annularmovement of the spaced plates during long term operation of the springdevice. Orlowski also must remove four of his coil springs to providespace for integral hooks used to maintain the plates relative to oneanother. As a result, the force produced by the Orlowski spring deviceis not maximized and is not balanced. The spring assembly in copendingapplication Ser. No. 10/078,465 is a different mechanism to overcome thedeficiency of Orlowski regarding circumferential shifting. But, thisdesign uses spaces which should accept coil springs.

THE INVENTION

[0004] The present invention relates to a ring-shaped spring device asshown in Orlowski wherein there are a plurality of locking assemblieslocated at circumferentially spaced positions around the ring that areeach within one of the coil spring's center passage. In this respecteach of these lock assemblies includes a first element extending fromone of the plates toward the other plate, a second element extending inthe opposite direction from the other plate to form a generally slidingcontact between the first and second elements as the spaced plates movevertically to compress and release the coil springs. The first andsecond elements are sized and shaped to fit within the center passage ofthe coil spring. This configuration maximizes the force produced by thering shaped spring device and balances the circumferentially extendingspring action.

[0005] In accordance with another aspect of the present invention, thefirst and second elements or tabs include a guiding mechanism torestrict annular movement at the plates relative to one another. Thefirst tab having a guide slot with a given width and which extends in adirection perpendicular to the plates. The second tab having a hookshaped guide member which extends through the guide slot to restrict thevertical movement between the two plates. The width of the hookcorresponds with the width of the slot which provides the guidingmechanism between the two plates. The structure assembly procedure andoperation of the present invention is different than the ring shapedspring device in Orlowski. These added features further result in theadvantage of being capable of maintaining the proper annular orientationbetween the spaced plates during long term operation of the springdevice in an automatic transmission.

[0006] Still another aspect of the present invention, the guide slot hasan end remote from the plate from which the second tab extends. Thedistance of this end from the plate maintains the coil springs in acompressed or prestressed condition when the device is assembled.

[0007] Yet another aspect of the present invention, by providing a tabwhich is sized to fit within the center passage of a coil spring, one ofthe annular support plates can be omitted. In its place are disk shapedpressure plates for each coil spring which reduces weight. Each of thedisk plates includes a locking tab surface that maintains the disk plateand spring relative to the remaining annular plate.

[0008] Even yet another aspect of the present invention, there are aneven number of locking assemblies around the circumference of theannular plates. One group of locking assemblies has the first tabextending from the first plate and the second group has the first tabextending from the second plate. By using two groups of lockingassemblies, the tabs of a plate alternate between a tab with the guideslot and a tab with the hook. The tabs may be integrally formed in theguide plates as in Orlowski. In the one embodiment, four lockingassemblies are used wherein the integral tabs at the twelve o'clockposition and six o'clock position have one construction and the tabs atthe three o'clock position and nine o'clock position have the oppositeconfiguration. By merely indexing the plates 90°, identical plates canbe used in constructing the ring shaped spring device.

[0009] Yet a further aspect of the present invention relates toutilizing molded tab components which incorporate one-way barbs orlocking tabs to maintain the plates relative to one another. In thisrespect, one of the annular plates includes a plurality of spacedreceptacles corresponding to the position of the coil springs. Thereceptacles are sized so that the coil springs fit about the receptacle.The other annular ring includes posts which also correspond to theposition and number of coil springs. The receptacle is shaped to receivethe post and includes one-way or locking barbs such that once the postenters the receptacle, it can not be removed.

[0010] Another aspect of the present invention involves spring tabs tolocate the coil springs around the annular plates. These spring tabs arelanced from the edge of the annular plates and are bent downwardly atcircumferentially spaced locations around the plates. The tabs are bentdownwardly from a point generally at the midpoint of the plates, wherebythe coil springs are located by the tabs in or near the center of theannular plates. This configuration allows the spring tabs to be producedby a simple punch press operation that first lances and then bends thetabs relative to the plate. This operation is much simpler than thecomplex bending operation required in Orlowski.

[0011] An object of the present invention is the provision of animproved ring-shaped spring device having two annular plates used tocapture and locate circumferentially spaced coil springs, wherein thespring device guides the movement of the annular plates as the springsare compressed and/or released and solving the deficiencies of OrlowskiU.S. Pat. No. 5,306,086.

[0012] Another object of the present invention is the provision of aspring device which utilizes locking assemblies that fit within thecenter passage of one of the coil springs so as to maximize the numberof springs that can be utilized and balancing the spring action aroundthe assembly.

[0013] Yet a further object of the present invention is the provision ofa ring-shaped spring device wherein spaced annular plates are heldtogether by lock assemblies having members that limit the movementbetween the plates to a generally vertical sliding movement as theplates move vertically to compress and/or release the coil springs, sothe plates are fixed in a circumferential direction.

[0014] Even yet a further object of the present invention is theprovision of replacing one annular ring with independent disk shapedpressure plates corresponding to each coil spring.

[0015] Another aspect of the present invention is the provision ofutilizing molded components having one-way or locking barbs that can beeasily snap-fitted together.

[0016] Even yet another object of the present invention is the provisionof eliminating one annular ring by utilizing coil spring which caninterengage with the other annular ring.

[0017] These and other objects and advantages will become apparent fromthe following description taken together with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0018]FIG. 1 is a top plan view of the ring shaped spring deviceconstructed in accordance with an embodiment of the present invention;

[0019]FIG. 2 is an enlarged cross-sectional view taken generally alongline 2-2 of FIG. 1;

[0020]FIG. 2A is an enlarged cross-sectional view taken generally alongline 2-2 of FIG. 1, however, the top hook tab is formed from materialnear the inner rim of top annular ring;

[0021]FIG. 3 is a cross-sectional view taken generally along line 3-3 ofFIG. 2;

[0022]FIG. 3A is a cross-sectional view taken generally along line 3A-3Aof FIG. 2A;

[0023]FIG. 4 is an enlarged exploded partial view of the spring deviceshown in FIG. 1;

[0024]FIG. 5 is an enlarged cross-sectional view of another embodimentof a ring shaped spring device according to the present invention;

[0025]FIG. 6 is a cross-sectional view taken generally along line 6-6 ofFIG. 5;

[0026]FIG. 7 is a top plan view showing another embodiment of a ringshaped spring device according to the present invention;

[0027]FIG. 8 is an enlarged cross-sectional view taken generally alongline 8-8 of FIG. 7;

[0028]FIG. 9 is an enlarged cross-sectional view taken generally alongline 9-9 of FIG. 7;

[0029]FIG. 10 is an enlarged exploded partial perspective view of thering-shaped device shown in FIG. 7;

[0030]FIG. 11 is a top plan view of yet another embodiment of a ringshaped spring device according to the present invention;

[0031]FIG. 12 is an enlarged cross-sectional view taken generally alongline 12-12 of FIG. 11;

[0032]FIG. 13 is an enlarged cross-sectional view taken generally alongline 13-13 of FIG. 11;

[0033]FIG. 14 is an enlarged cross-sectional view taken generally alongline 14-14 of FIG. 11;

[0034]FIG. 15 is an enlarged cross-sectional view taken generally alongline 15-15 of FIG. 11;

[0035]FIG. 16 is an enlarged exploded partial perspective view of thespring device shown in FIG. 11;

[0036]FIG. 17 is a top plan view of even yet another embodiment of aspring shaped spring device according to the present invention;

[0037]FIG. 18 is an enlarge cross-sectional view taken generally alongline 18-18 of FIG. 17;

[0038]FIG. 19 is a cross-sectional view taken generally along line 19-19of FIG. 18;

[0039]FIG. 20 is an exploded partial perspective view of the springdevice shown in FIG. 17;

[0040]FIG. 21 is a top plan view of still yet a further embodiment of aring shaped spring device according to the present invention;

[0041]FIG. 22 is an enlarged cross-sectional view taken generally alongline 22-22 of FIG. 21; and,

[0042]FIG. 23 is an exploded partial perspective view of the springdevice shown in FIG. 21.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0043] Referring now to the drawings, wherein the showings are for thepurpose of illustrating preferred embodiments of the invention only andnot for the purpose of limiting same, FIGS. 1, 2, 3 and 4 show a ringshaped spring device 8 having annular spaced-apart plates 10, 12 withouter rims 14, 16, respectively, and inner edges 15, 17. Plates 10, 12are coaxial to axis 18 and include spring tabs 20 of plate 10 and springtabs 22 of plate 12. The tabs, sometimes called “elements”, are lancedfrom a center portion of its respective plate and are bent to locate atcircumferentially spaced positions a number of coil springs 30. Thespring tabs 20, 22 have spaced distal edges 20 a, 22 a facing oneanother and have a length such that there is a gap between edges 20 a,22 a when device 8 as a whole is in a free state. Edges 20 a, 22 aengage one another to limit the vertical movement of plates 10, 12toward one another. The widths W of the spring tabs are just slightlysmaller than the diameters of passages 32 of springs 30. Any number oftabs and springs can be circumferentially spaced around plates 10, 12.In a preferred embodiment, twenty-four springs are employed and areequally spaced around plates 10, 12. The tabs or elements extend throughthe springs so there is no circumferential gap in the circular array ofcoil springs.

[0044] Four lock assemblies 40, 42, 44 and 46 are utilized to maintainplates 10, 12 relative to one another and are positioned within centerpassages 32A, 32B, 32C and 32D of coil springs 30A, 30B, 30C and 30Drespectively. By positioning the lock assemblies within the coilsprings, four additional coil springs can be utilized thereby increasingthe possible overall spring force of spring device 8 without changingthe design of coil springs 30. All lock assemblies 40, 42, 44 and 46 areessentially the same, however, the orientation of the assemblies isalternated one lock assembly to the next which allows plates 10, 12 tobe identical. In this respect, while each lock assembly is structurallythe same, lock assemblies 40, 44 are oriented in one direction and lockassemblies 42, 46 are oriented in the opposite direction. Plates 10, 12are merely positioned facing each other and are rotated 90° relative toone another about axis 18 to properly align lock assemblies 40, 42, 44and 46. The advantage of this concept is that by using identical plates,manufacturing and inventory costs can be reduced.

[0045] Since all lock assemblies 40, 42, 44 and 46 are structurally thesame, only lock assembly 40 will be described in detail and thisdescription applies to the other lock assemblies 42, 44 and 46. However,as stated above, assemblies 42, 46 are oriented differently. Lockassembly 40 includes hook tabs 50, 52 which are provided on the oppositeplates 10, 12. Tabs 50, 52 are created by forming a lanced portion ofplates 10, 12, respectively, wherein tabes 50, 52 are still attached toplates 10, 12, at bases edges 54, 56 respectively. Turning to tab 50, itis lanced from an outer portion of plate 10 such that there is a gap inplate 10 from base edge 54 which extends radially outwardly to rim 14.Tab 50 is bent at base edge 54 at a 90 degree angle from plate 10 towardplate 12 and includes a base portion 66, an extension 68 and a distalend 58. Tab 50 further includes a hook 62 on distal end 58 which isopened toward outer rim 14. Tab 52 is lanced from an inner portion ofplate 12 such that there is a gap in ring 12 from base edge 56 whichextends radially inwardly to edge 17. Tab 52 is bent at base edge 56 ata 90 degree angle from plate 12 towards plate 10 and includes baseportion 70, an extension 72 and a distal end 60. Tab 52 further includesa hook 64 on distal end 60 which is opened toward inner edge 17. Whenplates 10, 12 are move vertically toward one another, hooks 62, 64 passover each other and then prevent the plates 10, 12 from being separatedvertically. As a result, plates 10, 12 can move vertically relative toone another, however, hooks 62, 64 prevent separation of the plates. Thelength of tabs 50, 52 determine the free-state height of device 8 as awhole and maintain the springs in a prestressed condition. In thisrespect coil springs 30 have a free-state spring height which isdifferent than the overall free-state height of device 8. The free-statespring height is achieved when coil springs 30 are unstressed andallowed to extend to a maximum spring height (not shown). The gapbetween plates 10, 12 is less than the free-state height for coilsprings 30 when hooks 62, 64 are interengaging with one another.Accordingly, spring 30 is exerting a force against plates 10, 12 evenwhen the overall spring device 8 is in its unstressed or free-statecondition. When an external force is applied to spring device 8, plates10, 12 move vertically downwardly toward one another and hooks 62, 64disengage. As discussed above, the downward vertical motion is limitedby edges 20 a, 22 a of spring tabs 20, 22 respectively.

[0046] In the following discussions concerning other embodiments, thecomponents of the spring device which remain the same, as discussedabove, will include the same reference numbers as above.

[0047] Referring to FIGS. 2A and 3A, Lock assembly 40 a is shown whichworks the same was as lock assembly 40 except it includes hook tabs 52and 50 a. While tab 52 is the same as describe above, tab 50 a is lancedfrom an inner portion of plate 10 a such that there is a gap in ring 10a from base edge 54 a which extends radially inwardly to edge 15. Tab 50a is bent at base at a 90 degree angle from plate 10 a toward plate 12.Tab 50 a is bent at base edge 54 a and includes a distal end 58 a with ahook 62 a which is opened toward outer rim 14 just like hook 62. Theonly difference being that tab 50 a is formed from an inner portion ofplate 10 a while tab 50 is formed from the outer portion. In similarfashion as assembly 40, when plates 10 a, 12 are move vertically towardone another, hooks 62 a, 64 pass over each other and then prevent theplates 10 a, 12 from being separated vertically.

[0048] Referring to FIGS. 5 and 6, a ring shaped spring device 100 isshown which is essentially the same as device 8 above except for amodification to the locking assemblies. More particularly, spring device100 includes annular spaced-apart plates 10, 102 with outer rims 14,104, respectively. Plates 10, 102 are coaxial to axis 18 and includespring tabs 20 (not shown) of plate 10 and spring tabs 22 (not shown) ofplate 102 which are configured the same as above and therefore will notbe discussed in detail. Any number of tabs and springs can becircumferentially spaced around plates 10, 102. In a preferredembodiment, twenty-four springs are employed and are equally spacedaround plates 10, 102.

[0049] Four lock assemblies 110, 112, 114 and 116 (only 110 is shown)are utilized to maintain plates 10, 102 relative to one another. As withdevice 8, assemblies 110, 112, 114 and 116 are structurally the sameexcept that they are oriented differently to allow plates 11, 102 to beidentical. Therefore only assembly 110 will be described in detail andthis description applies to the other lock assemblies 112, 114 and 116.Assembly 110 is positioned within center passage 32A of coil spring 30Aand includes hook tab 50, described above, and slot tab 122. Slot tab122 is formed from an inner portion of plate 102 and extends from a baseedge 124 to a distal end 126. Tab 122 extends at a 90° angle from plate102 toward plate 10 and has a maximum width 128 allowing it to fitwithin center passage 32A. Extending vertically in tab 122 is anelongated slot 130 having a width 132, a length 134 and a slot edge 136near distal end 126. Side edges 138, 140 are essentially parallel to oneanother and extend from either side of slot edge 136 toward plate 102.Tab hook 62 along with extension 68 have essentially a common widthwhich is slightly smaller than slot width 132 such that hook 62 canextend through slot 130. Accordingly, when plates 10, 102 are assembled,hook 62 first engages slot tab 122 and then enters slot 130. Once inslot 130, the engagement between hook 62 and slot edge 136 preventsseparation of plates 10, 102. In addition, the length of tab 50 and slot130 determine the free-state height of device 100 as a whole andmaintains springs 30 in a prestressed condition. Movement of plates 10and 102 relative to one another about axis 18 is controlled by theengagement between hook 62 and slot edges 138, 140. In this respect,hook 62 has hook edges 142, 144 and rotation is prevented in onedirection by the engagement between slot edge 138 and hook edge 142 andin the other direction by the engagement between hook edge 144 and slotedge 140.

[0050] Referring now to FIGS. 7-10, a ring shaped spring device 200 isshown which includes only one annular plate 202. Plate 202 includes anouter rim 204 and an inner edge 205. Plate 202 further includes springtabs 206 which are lanced from an inner portion of plate 202 whereintabs 206 are still attached to plate 202 at base edges 207. In thisrespect, tabs 206 are formed by an inner portion of plate 202 such thatthere is a gap in plate 202 from base edge 207 which extends radiallyinwardly to edge 205. Tabs 206 are bent at a 90 degree angle at baseedge 207 from plate 202. The widths W of the spring tabs are smallerthan the diameters of the passages 208 of springs 210. Any number oftabs and springs can be circumferentially spaced around plate 202. In apreferred embodiment, twenty-four springs are employed and they areequally spaced around plate 202.

[0051] Each spring tab 206 includes a vertically extending slot 212having a top edge 214, a bottom edge 216 and parallel side edges 218 and220. Each spring 210, is made from a single wire 228 and includes abottom edge 230 which rests on plate 202 and a top edge 232 spaced frombottom edge 230. Spring 210 further includes extension 234 which is acontinuation of wire 228 and which extends downwardly into centerpassage 208. At the end of extension 234 is a hook 238 shaped and sizedto enter slot 212. Spring 210 is assembled to plate 202 by urging spring210 over tab 206 and partially compressing spring 210 until hook 238enters slot 212. Once hook 238 enters slot 212 it maintains spring 210relative to plate 202 in a prestressed condition with spring bottom 230engaging plate 202. As spring 210 is compressed by the transmission,hook 238 rides in slot 212 between top and bottom edges 214, 216respectively.

[0052] Referring now to FIGS. 11-16, yet even another embodiment isshown. Shown is a ring shaped spring device 300 having annular spacedapart plates 302, 304 with outer rims 306, 308, and inneredges 307,309,respectively. Device 300 includes spring tabs 310 for plate 302 andspring tabs 312 for plate 304 which are each lanced from an innerportion of plates 302, 304, respectively, wherein tabs 310 are attachedto plate 302 at bases edges 314 and tabs 312 are attached to plate 304at base edges 316. In this respect, tabs 310 are formed from an innerportion of the plates between base edges 314, 316 and inner edges 307,309 respectively. Tabs 310, 312 are bent at a 90 degree angle at baseedges 314, 316. The widths W of the spring tabs are smaller than thediameters of passages 32 of springs 30. Any number of tabs and springscan be circumferentially spaced around plates 302, 304. In a preferredembodiment, twenty-four springs are employed and are equally spacedaround plates 302, 304. Spring tabs 310, 312 have spaced distal edges317, 318 facing one another and have a length such that there is a gapbetween edges 317 and 318 when device 300 as a whole is in a free state.Edges 317, 318 engage one another to limit the vertical movement ofplates 302, 304 toward one another.

[0053] Four lock assemblies 320,322,324 and 326 are positioned aboutplates 302,304. While four such assemblies are shown, as with the otherembodiments, a different number of assemblies could be utilized. As withprevious embodiments, assemblies 320, 322, 324 and 326 are structurallythe same except that they could be oriented differently to allow plates302, 304 to be identical. Therefore only assembly 320 will be describedin detail and this description applies to the other lock assemblies 322,324 and 326. Referring with particular reference to FIGS. 14, 15 and 16,lock assembly 320 includes a hook tab 350 and a notch tab 352. Tabs 350,352 are created by forming a lanced portion of plates 302, 304,respectively, wherein tabes 350, 352 are still attached to plates302,304 at bases edges 354,356 respectively. Turning to tab 350, it islanced from an inner portion of plate 302 such that there is a gap inplate 302 from base edge 354 to inner edge 307. Tab 350 is bent at baseedge 354 ninety degrees from plate 302 toward plate 304 and includes abase portion 358, an extension 360 and a distal end 362. Extension 360has a width which is approximately half the width of base portion 358and further, extension 360 extends from one side of base portion 358thereby making hook tab 350 L-shaped. Tab 350 further includes a hook364 on distal end 362 which is opened toward inner edge 307. Tab 352 islanced from an inner portion of plate 304 such that there is a gap inring 304 from base edge 356 to edge 309. Tab 352 is bent at base edge356 ninety degrees from plate 304 toward plate 302 and is essentiallyC-shaped having outer side edges 366, 368 which extend from plate 304towards distal end 370 of tab 352. Side edge 368 includes a notch 372having parallel notch edges 374, 376 that are joined by vertical notchedge 378. The length of notch edges 374,376 corresponds with the widthof hook 364. With particular reference to FIG. 15, by utilizing L-shapedhook tab 350 and C-shaped notch tab 352, assembly 320 can fit withinspring cavity 32 and can be assembled without forcing hook 364 to deformin order to pass over its engagement point on notch tab 352. In thisrespect, while within cavity 32, hook 364 can be manipulated to passnext to edge 368 and then to be positioned within notch 372. As hook 364is being manipulated into notch 372, spring 30 is partially compressed.Once in notch 372, spring 30 forces plates 302 and 304 away from oneanother until hook 364 engages edge 374.

[0054] Referring now to FIGS. 17-20, a ring shaped spring device 400 isshown which includes annular spaced apart plates 402,404 with outer rims406,408 and inner edges 407,409, respectively. Spring device 400 isshown to include twenty-four lock assemblies 410, however, it should benoted that less than twenty-four lock assemblies could be used and lessthan twenty-four coil springs 30 could be used. However, it is preferredthat all twenty-four springs 30 are used in connection with twenty-fourlock assemblies 410. Lock assemblies 410 are all identical and eachincludes a receptacle 412 and a post 414. Receptacle 412 is cylindricalwith a base end 420 secured to plate 404 and which extends toward plate402. Receptacle 412 has a distal end 422 spaced from end 420 thatincludes an opening 424 to an inner portion 428. Receptacle 412 furtherincludes several barbs 426 that extend downwardly into inner portion428. Post 414 includes a base 430 connected to plate 402 and extendstoward plate 404. In addition, post 414 includes a tapered lead 432which is shaped to urge barbs 426 outwardly and allow a portion of post414 to enter inner portion 428. Post 414 further include locking groove434 having a cylindrical portion 436 and a frustum conical portion 438adjacent to cylindrical portion 436. As a result, once tapered lead 432urges barbs 426 outwardly and allows the end of post 414 to enter innerportion 428, barbs 426 spring into locking groove 434 thereby retainingpost 414 relative to receptacle 412. Cylindrical portion 436 providesfor the compression of spring 30 by allowing post 414 to move downwardlyinto inner portion 428. However, barbs 426 do not allow post 414completely pull out of inner portion 428. Furthermore, the verticaldimensions of post 414 and receptacle 412 are such that when barbs 426engage edge 440, springs 30 remain in a prestressed condition. Inaddition, the engagement between the post and the receptacle preventrotational movement of plate 402 relative to plate 404 about axis 18.

[0055] Referring to FIGS. 21-23, a ring shaped spring device 500 isshown which includes only a single annular plate 404 as described above.Spring device 500 further includes twenty-four receptacles 412 which arethe same as described above with respect to spring device 400. However,device 500 includes twenty four independent post assemblies 508. Whileeach post assembly 508 includes posts 414 as described above, each postassembly 508 is joined to a post disk 510 that has a diameter greaterthan the outer diameter of springs 30. This results in each postassembly 508 moving independent of one another. The functionalrelationship between post 414 of assemblies 508 and receptacle 412 isalso the same as described above with respect to spring device 400 andtherefore will not be described in detail.

[0056] While considerable emphasis has been placed on the preferredembodiments of the invention illustrated and described herein, it willbe appreciated that other embodiments can be made and that many changescan be made in the preferred embodiments without departing from theprinciples of the invention. Accordingly, it is to be distinctlyunderstood that the foregoing descriptive matter is to be interpretedmerely as illustrative of the invention and not as a limitation.

Having thus defined the invention, it is claimed:
 1. A spring devicecomprising a pair of spaced-apart first and second annular supportplates defining a ring with a central ring axis; a plurality ofcircumferentially spaced, parallel oriented coil springs disposedbetween said annular plates and having associated therewith a free-stateheight for said coil springs, said coil springs being coiled about aspring axis which defines a spring center passage; and, a plurality oflock assemblies located at circumferentially spaced positions aroundsaid ring, each of said lock assemblies being within one of said centerpassages and including a first tab extending from one of said platestoward a first distal end facing the other of said plates, a second tabextending from said other of said plates toward a second distal endfacing said one of said plates, said first distal end being curvedtoward said axis to form an inwardly facing hook, said second distal endbeing curved away from said axis to form an outwardly facing hook andfacing said inward hook, said inward and outward hooks interengaging toallow said plates to move toward or away from each other to compressand/or release said coil springs but preventing said coil springs fromreaching said free-state height.
 2. A spring assembly, as defined inclaim 1, wherein said tabs are formed integrally of said plate fromwhich they extend.
 3. A spring device comprising a pair of spaced-apartfirst and second annular support plates defining a ring with a centralaxis; a plurality of circumferentially spaced, parallel oriented coilsprings disposed between said annular plates and having associatedtherewith a free-state height for said coil springs, said coil springbeing coiled about a spring axis which defines a spring center passage;and, a plurality of lock assemblies located at circumferentially spacedpositions around said ring, each of said lock assemblies being withinone of said center passages and including a first tab extending from oneof said plates toward a distal end facing the other of said plates, asecond tab extending from said other of said plates toward said one ofsaid plates, said distal end being curved to form a hook having a widthand which faces said second tab, said second tab having a locking slotwith a given width greater than said hook width and extending in adirection perpendicular to said plates, said hook extending through saidslot to allow said plates move toward and away from each other tocompress and/or release said coil springs, said hook engaging said slotto prevent said coil springs from reaching said free-state height.
 4. Aspring assembly, as defined in claim 3, wherein said tabs are formedintegrally of said plate from which they extend.
 5. A spring devicecomprising a pair of spaced-apart first and second annular supportplates defining a ring with a central ring axis; a plurality ofcircumferentially spaced, parallel oriented coil springs disposedbetween said annular plates and having associated therewith a free-stateheight for said coil springs; and, a plurality of lock assemblieslocated at circumferentially spaced positions around said ring, each ofsaid lock assemblies including a first tab extending from one of saidplates toward a distal end facing the other of said plates, a second tabextending from said other of said plates toward said one of said plates,said distal end being curved to form a hook having a width and whichfaces said second tab, said second tab having a locking slot with agiven width generally matching, but slightly larger than said hook widthand extending in a direction perpendicular to said plates and said hookextending through said slot to allow said plates to move toward and awayfrom each other to compress and/or release said coil springs, said hookengaging said slot to prevent said coil springs from reaching saidfree-state height, and to prevent relative rotation between said annularplates about said ring axis.
 6. A spring assembly, as defined in claim5, wherein said tabs are formed integrally of said plate from which theyextend.
 7. A spring device comprising an annular support plate defininga ring with a central ring axis; a plurality of circumferentiallyspaced, parallel oriented coil springs disposed on one side of saidannular plate and having associated therewith a free-state height forsaid coil springs, each of said coil springs including a first endengaging said one side and a second end spaced from said one side, saideach spring being formed by a unitary wire coiled about a spring axisbetween said first and second ends which defines a spring centerpassage, said each spring further including a wire extension formed bysaid unitary wire which extends from said second end into said centerpassage toward said first end, said extension having a spring hook; and,a plurality of tabs located at circumferentially spaced positions aroundsaid ring, each of said tabs extending from said plate into said centerpassage of a respective said each spring and has a guide slot extendingin a direction perpendicular to said plate, said spring hook extendingthrough said slot to maintain said each spring relative to said plateand to prevent said each spring from reaching said free-state height. 8.A spring assembly, as defined in claim 7, wherein said tabs are formedintegrally of said plate from which they extend.
 9. A spring devicecomprising a pair of spaced-apart first and second annular supportplates defining a ring with a central ring axis; a plurality ofcircumferentially spaced, parallel oriented coil springs disposedbetween said annular plates and having associated therewith a free-stateheight for said coil springs, each said coil spring being coiled about aspring axis which defines a spring center passage; and, a plurality oflock assemblies located at circumferentially spaced positions aroundsaid ring, each of said lock assemblies being within one of said centerpassages and including a first tab extending from one of said platestoward a first distal end facing the other of said plates, a second tabextending from said other of said plates toward said one of said plates,said distal end including a hook, said second tab having parallel sidesextending from said other plate, one of said parallel sides including anotch having opposing notch edges transverse to said parallel sides,said hook extend into said notch such that said plates move toward andaway from each other to compress and/or release said coil springs, saidhook engages one of said notch edges to prevent said coil springs fromreceiving said free-state height.
 10. A spring assembly, as defined inclaim 9, wherein said tabs are formed integrally of said plate fromwhich they extend.
 11. A spring device comprising a pair of spaced-apartfirst and second annular support plates defining a ring with a centralring axis; a plurality of circumferentially spaced, parallel orientedcoil springs disposed between said annular plates and having associatedtherewith a free-state height for said coil springs, each said coilspring being coiled about a spring axis which defines a spring centerpassage; and, a plurality of lock assemblies located atcircumferentially spaced positions around said ring, each of said lockassemblies including a receptacle having a base connected to one of saidplates and distal end extending toward the other of said plates, saiddistal end including a plurality of locking barbs, a post extending fromsaid other of said plates toward said one of said plates, said posthaving a base connected to said other plate and a distal end having atapered tip shaped to pass said barbs and a locking groove, said barbsinterengaging with said groove to maintain said post in said receptaclewhile allowing said plates move relative to one another to compressand/or release said coil springs, said interengagement preventing saidcoil springs from reaching said free-state height and to preventrelative rotation between said annular rings about said ring axis.
 12. Aspring assembly, as defined in claim 11, wherein said each lock assemblyis within one of said spring passages.
 13. A spring device comprising anannular support plate defining a ring with a central ring axis; aplurality of circumferentially spaced, parallel oriented coil springsdisposed on one side of said annular plate and having associatedtherewith a free-state height for said coil springs; a plurality ofreceptacles located at circumferentially spaced positions around saidplate, each of said receptacles having a base connected to said plateand a distal end extending outwardly from said plate, said distal endincluding a plurality of locking barbs; and a plurality of postscorresponding to said receptacles; each said post having a baseconnected to an individual spring plate and a distal end having atapered tip shaped to pass said barbs and a locking groove, said barbsinterengaging with said groove to maintain said post in said receptaclewhile allowing said spring plates to move 10 relative to said annularplate to compress and/or release said coil springs.
 14. A springassembly, as defined in claim 13, wherein said interengagement betweensaid barbs and said groove prevents said coil springs from reaching saidfree-state height.
 15. A spring device comprising at least one annularsupport plate defining a ring with a central ring axis; a plurality ofcircumferentialiy spaced, parallel oriented coil springs disposed on oneside of said at least one plate and having associated therewith afree-state height for said coil springs, said coil springs being coiledabout a spring axis which defines a spring center passage and having afirst end engaging said one side and a second end spaced from said firstend; and, a plurality of lock assemblies located at circumferentiallyspaced positions around said ring, each of said lock assemblies beingwithin one of said center passages, said plurality of lock assembliesmaintaining said engagement between said first end and said one side butpreventing said coil springs from reaching said free-state height.
 16. Aspring assembly, as defined in claim 15, wherein said first and secondtabs are formed integrally of said plate from which they extend.
 17. Aspring device comprising a pair of spaced-apart first and second annularsupport plates defining a ring with a central ring axis; a plurality ofcircumferentially spaced, parallel oriented coil springs disposedbetween said annular plates and having associated therewith a free-stateheight for said coil springs, said coil springs being coiled about aspring axis which defines a spring center passage; and, a plurality oflock assemblies located at circumferentially spaced positions aroundsaid ring, each of said lock assemblies being within one of said centerpassages and including a first element extending from one of saidplates, a second element extending from said other of said plates, saidfirst and second elements interengaging to allow said plates to movetoward or away from each other to compress and/or release said coilsprings but preventing said coil springs from reaching said free-stateheight.
 18. A spring assembly, as defined in claim 17, wherein saidelements are formed integrally of said plate from which they extend.